Gumbricht, T., 2004. Spatial data and geographic information systems. (eds: B.K. Patel., K. Muir-Leresche, R. Coe & S.D. Hainsworth) , The Green Book: A guide to effective graduate research in Africa agriculture, environment, and rural development., 129-142. The African Crop Science Society. Kampala. Load pdf in frame or go to the pdf (or right click the latter and 'Save Link As ...').